1. Field of the Invention
The present invention related to a screen used for partitioning a room, and more particularly to a screen of this kind equipped with an air cleaner or a fan so as to have an air cleaning function.
2. Description of the Prior Art
Screens are widely utilized because of the following advantages. First, a screen can be installed for partitioning a room more easily than a wall because architectural tools are not necessary. The screen can be easily moved and removed in accordance with a change in usage of the room. An appropriate height of the screen which does not extend up to the ceiling provides good visibility and does not give an restrictive feeling so that people feel free from isolation. Since the conventional screen is used only for the purpose of partitioning a room, it does not produce any other effect than defining a space from the floor to a certain height. However when conventional screens are used to partition a room into a plurality of sections, contaminated air (e.g., cigarette smoke, bad air, toxic gases or the like) or odors may flow into a section from the outside or from another section through the space between the top of the screens and the ceiling since air is allowed to flow freely between the sections through this space.
To solve the above problems, the prior art has proposed: (1) A screen with air curtain (Japanese Laid-open Utility Model Application No. 1-114874, hereinafter "JP 874"); and (2) A screen with an air cleaner and an air curtain (Japanese Laid-open Patent Application No. 2-45014, hereinafter "JP 014").
JP '874 discloses a screen body having an air blowing outlet on a upper portion and an air inlet on a lower portion; and a fan arranged inside this screen body. In this prior art example, one or more screen bodies are installed to surround part of a room with their air inlets directed inwardly, air is drawn from the air inlets of the screen bodies through the fan and discharged from the air blowing outlets to form an air curtain above the screen bodies, whereby a space or part of the room is defined by this air curtain and the screen bodies, with the result that air possibly contaminated in this space is prevented from flowing to the outside.
JP '014 discloses an air blowing outlet on a screen body for forming an upwardly directing air curtain; an air inlet and an air discharging port on one surface and the opposite surface of the screen body, respectively; an air cleaner and a fan between the air discharging port and the air inlet; and an airflow amount adjuster arranged on the downstream side of the fan in the screen body for adjusting an amount of air discharged from the air discharging port. One or more screens are installed to surround part of a room, with the air inlets directed inwardly, to thereby define a space or the part of the room by this air curtain and the screen bodies. Further, when air is discharged from the air discharging port, the discharged air amount is adjusted by the airflow amount adjuster so as to be larger than an amount of air which is involved in the space from the outside, whereby a negative pressure state is established in the space to prevent contaminated air in this space from flowing to the outside to maintain the cleanliness of the whole room except for this space.
However, in JP '874 since the airflow amount is increased as the air curtain blowing up from above the screen bodies involves air from both inside and outside the space defined by the screens and the air curtain, cigarette smoke and other pollutants, if produced in this space will be mixed in the air curtain. To prevent such contaminated air from flowing to the outside of the space, additional facilities such as an air intake pipe and an air discharger are required for discharging, from the ceiling for the floor located in the space, an amount of air larger than an amount of air involved from the outside of the space by the air curtain. Furthermore, by installing these facilities, it becomes necessary to maintain a negative pressure state inside the space.
JP '014 is advantageous in removing the necessity of additionally installing an air intake pipe and an air discharger on the ceiling, holding a space in a room surrounded by the screen bodies and the air curtain in a negative pressure state, and maintaining the cleanliness of the space. However, since this prior art reference produces a pressure loss caused my airflow amount adjuster such as a damper which adjusts the amount of air discharged from the air discharging port, a larger fan and a high-power motor are required in order to maintain a predetermined amount of discharged air and an air amount required to form an air curtain.